Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Dave Goerig, Tim Malinich, Jane Martin, Hannah Mathers, Pam Sherratt, Amy Stone, and Curtis Young
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May 12, 2005
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This is the Sixth 2005 edition of the Buckeye Yard and Garden Line (BYGL).
BYGL is developed from a Tuesday morning conference call of Extension
agents, specialists and other contributors in Ohio.
BYGL is also made available on the Internet from the Ohio State University
Horticulture and Crop Science (HCS) in Virtual Perspective website
(http://bygl.osu.edu). Additional fact sheet information on any of
these articles may be found through the OSU fact sheet database (http://plantfacts.osu.edu).
BYGL is a service of OSU Extension and is aided by major support
from the Ohio Nursery and Landscape Association (ONLA), with additional
funding from the Ohio Chapter of the International Society of Arboriculture
(ISA) to the OSU Extension Nursery Landscape, and Turf Team (ENLTT).
Participants in the May 10, 2005 conference included: Pam Bennett (Clark); Barb Bloetscher (Entomology, C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)); Joe Boggs (Hamilton /Center at Piketon); Jim Chatfield (Center at Wooster/Horticulture and Crop Science [HCS]); Erik Draper (Geauga); Dave Dyke (Hamilton); Amy Fulcher, University of Kentucky, Department of Horticulture; Dave Goerig (Mahoning); Tim Malinich (Cuyahoga); Joe Rimelspach (Plant Pathology, CWEPPDC); Pam Sherratt (HCS); Dave Shetlar (Entomology); Amy Stone (Lucas); Curtis Young (Allen) and Randy Zondag (Lake)..
Additional factsheet information on any of these articles may be found
through the OSU Factsheet Database (http://plantfacts.ohio-state.edu/)
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WEATHER WATCH
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Mothers and gardeners enjoyed a beautiful Mother's Day weekend across Ohio. Although we all enjoyed the sun, there were big weather differences from north to south. The snow has melted in the NE, but cooler than average temperatures have made people anxious to enjoy more springtime blooms.
Here is the weather summaries from selected OARDC weather stations across the buckeye state. The information is a summary of data collected from May 1 - May 11.
| Weather Station |
Region of Ohio |
Ave. High Temp F | Ave. Low Temp F | Ave. Temp F | Normal Ave. Temp F | Total Precip " | Normal Precip " | | Perry |
NE |
61.3 |
41.3 |
N/A | N/A |
0.35" |
N/A | | Hoytville |
NW |
67.1 |
38.6 |
53.8 |
56.1 |
0.02" |
1.05" |
| Columbus |
Central |
68.5 |
41.5 |
55.9 |
58.0 |
0.04" |
1.39" |
| Miami |
SW |
70.2 |
42.9 |
57.1 |
58.0 |
0.00" |
1.7" |
| Jackson |
South |
69.9 |
37.3 |
53.9 |
58.3 |
0.01" |
1.38" |
For additional information, or to see the locations of all of the OARDC weather stations in Ohio,
check out the website at http://www.oardc.ohio-state.edu/centernet/weather.htm
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HORT SHORTS
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GDD (GROWING DEGREE DAYS)
GDD is a measure of the daily maximum and minimum temperature and directly relates to growth and development of plants and insects. The GDD of any zip code location in Ohio is estimated using the GDD of ten OARDC weather stations and available on the web at: http://www.oardc.ohio-state.edu/gdd/
The range of GDD accumulations in Ohio from north to south is 185 to 426. Following is a report of GDD for several locations around Ohio as of May 11, 2005: Painesville, 185; Cleveland, 190; Toledo, 256; Youngstown, 220; Lima, 259; Wooster, 276; Coshocton, 259; Columbus, 287; Springfield, 326; Dayton, 370; Cincinnati, 426; Ironton, 410; and Portsmouth, 411.
To put these GDD accumulations into perspective, the following is an abbreviated listing of plant and insect species with their respective phenological event and average GDD accumulations at which these events occur. Due to variations in weather, temperature, humidity, etc., these events may occur a few days earlier or later than predicted by the average GDD. By looking at a city, town, or village near you from the above list, or visiting the above web site, you can see what could be taking place in the landscape around you.
Koreanspice viburnum, first bloom, 185; regent serviceberry, first bloom, 186; Japanese flowering crabapple, first bloom, 189; eastern redbud, first bloom, 191; gypsy moth, egg hatch, 192; Koreanspice viburnum, full bloom, 205; azalea lace bug, egg hatch, 206; spring snow crabapple, full bloom, 209; common flowering quince, full bloom, 214; birch leafminer, adult emergence, 215; coral burst crabapple, first bloom, 217; elm leafminer, adult emergence, 219; common chokecherry, full bloom, 221; alder leafminer, adult emergence, 224; honeylocust plant bug, egg hatch, 230; common lilac, first bloom, 234; Ohio buckeye, first bloom, 245; common horse chestnut, first bloom, 251; hawthorn lace bug, adult emergence, 253; hawthorn leafminer, adult emergence, 260; flowering dogwood, first bloom, 263; red buckeye, first bloom, 265; blackhaw viburnum, first bloom, 269; imported willow leaf beetle, adult emergence, 274; sargent crabapple, full bloom, 298; red horsechestnut, first bloom, 304; pine needle scale, egg hatch - 1st generation, 305; cooley spruce gall adelgid, egg hatch, 308; eastern spruce gall adelgid, egg hatch, 308; common lilac, full bloom, 315; winter king hawthorn, first bloom, 328; lilac borer, adult emergence, 330; slender Deutsia, first bloom, 338; Japanese kerria, full bloom, 342; common horsechestnut, full bloom, 344; doublefile viburnum, first bloom, 353; red Java weigela, first bloom, 365; black cherry, first bloom, 368; lesser peach tree borer, adult emergence, 372; Ohio buckeye, full bloom, 374; holly leafminer, adult emergence, 375; Vanhoutte spirea, full bloom, 406; euonymus scale (first generation), egg hatch, 406; black cherry, full bloom, 419; Miss Kim Manchurian lilac, first bloom, 422; and locust leafminer, adult emergence, 437.
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SHIFTING YELLOWS
We reported in BYGL 2005-04 (4/28/05) that the dominant "yellow flower" shooting up from fields in southwest Ohio was GARDEN YELLOWROCKET (Barbarea vulgaris). While this member of the mustard family (Brassicaceae; a.k.a. Cruciferae) continues to be very evident, its ascendancy is now being challenged by CRESSLEAF GROUNDSEL (Senecio glabellus), (a.k.a. BUTTERWEED (Packera glabella)). Indeed, this member of the aster family (Asteraceae; a.k.a. Compositae) is the dominant yellow-flowering weed currently gracing fields in southern Ohio as well as southeast and central Indiana.
Unlike the tiny four-petaled mustard flowers of yellowrocket, the flowers of cressleaf groundsel are daisy-like and the seed heads look like miniature dandelion puff-balls. Flowers are enclosed by green bracts and are borne at the ends of thick, erect, stems that are green with reddish-purple streaks. The common name is based on the "cress-like" leaves.
Cressleaf groundsel is a winter annual that is native to the northern United States. However, for reasons that are not clearly understood, the weed has become unusually common in recent years in southern, central, and western Ohio in cultivated fields as well as in nurseries and landscapes. Some unplanted fields are now displaying an attractive bright yellow color due to the tremendous infestation of flowering cressleaf groundsel. The main concern is that the plant is poisonous to grazing livestock. Past reports indicate the weed may have some tolerance for 2, 4-D and may require high rates of glyphosate to be controlled.
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OH CRABLANDIA
Plant Discovery Day and Mother's Day this past weekend was a once in a decade crabaganza in the Crablandia II plot and other plantings at Secrest Arboretum; OSU's Ohio Agricultural Research and Development Center campus in Wooster. The cool spring temperatures this year and the fact that this is the boom year of the boom-bust years of crabapple bloom and the fact that the Crablandia II plot is just at the right size for viewing of the colors and shapes of 5-10 year old crabapple trees conspired to create the perfect storm for crabapple beauty. In the past few years the overall peak bloom for the plot was about a week earlier. However this year Mother's Day weekend was the peak of bud and bloom show.
Before the past week, blooms lagged behind due to the florist's cooler effects of our cool spring. On May 2 in 2004, for example, 45 of the 68 crabapple taxa in the plot were already at full bloom. This year there were only 5 at full bloom on May Day. With warmer weather starting the middle of last week ... that all changed and many crabapples burst into flower. As the First Earl of Pome-Roy said, "No genus of ornamentals so gracefully combines fruit, flower, foliage and from to such wondrous aesthetic appeale as the magical Malus, the crown jewelle of the rose family royale."
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WOODY PLANT OF THE WEEK
Our selection for early May is red buckeye (Aesculus pavia), nominated by that transplanted West Virginian, Joe Boggs. Red buckeye has our state tree Ohio buckeye (A. glabra) beat in that it has greater resistance to Guignardia leaf blotch disease, and thus has cleaner leaves throughout the summer. Apparently, Joe did not want to have anything to do with a specific epithet ("glabra") that means "hairless". So back to red buckeye, our almost-state tree, nominated from someone from almost-heaven."Red buckeye is a small Zone 5 tree (15-25 feet or more) with attractive palmate leaves and exotic bright red upright flower panicles. Red buckeye does well in partly shaded to sunny sites". This plant deserves more use in the landscape.
Why the quote marks with this description? Because it comes directly from the new publication Landscape Plants for Ohio published by the Ohio Nursery & Landscape Association. The descriptions and photographs of plants were provided for this new publication by the OSU Extension Nursery Landscape and Turf Team with great help from friends such as Bill Hendricks and Fred Hower and in partnership with ONLA.
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BUG BYTES
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THE LATEST BUZZ ON HONEY BEES
HONEY BEE SWARM calls have begun and will continue through May. Many counties have "swarm lists" composed by local beekeeping societies, listing the names and phone numbers of beekeepers who will collect the swarms. Normally the police and fire department have the lists as well as other public agencies. Since honey bee swarms are not likely to sting and considered a beneficial insect, all efforts should be made to find a beekeeper instead of exterminating them. In many cases, the swarm of bees will fly away if the swarm is exposed to the sun and wind. OSU, OARDC, has a list of beekeeping organizations to contact at: http://www.beelab.osu.edu/groups.asp
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PROTECTING BEES FROM THE STING
Growers are implored to avoid making applications of insecticides to flowering plants, vegetables, and fruits while they are in bloom so that honey bees and other pollinators are conserved. Fruit trees, especially, require honey bees to pollinate the flowers, yet when the bees visit flowers with an insecticide/fungicide residue the workers take the toxin back to the colony. This kills the bee and often spreads throughout the entire hive. Instead, treat the fruit trees at petal fall, as the fruit tree spray guides recommend. Treat flowering vegetables and ornamentals after the flowering has finished or direct the spray away from the flowers. Use of insecticidal soaps and oils, and directing the insecticide on the insect pests causing the damage will also spare the bees as well as other beneficial and predatory insects.
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ASIAN AMBROSIA BEETLE ACTIVITY IS EVIDENT
Amy Fulcher and Randy Zondag reported observing adult activity of the Asian ambrosia beetle (Xylosandrus crassiusculus ) in Kentucky and northeast Ohio, respectively. This non-native tree pest was first found in the U.S. in 1974, infesting peach trees in Charleston, South Carolina. It was first found in Ohio in 2002, infesting magnolia nursery stock. Randy indicated he observed beetle activity on heavily infested nursery stock that was subsequently destroyed. Amy noted that the beetle was first found in Kentucky in 2003, and her pest surveys have revealed the beetle in 6 counties with infestations occurring in both nursery stock as well as landscape trees.
The beetles are dark brown and small, measuring only 2 to 3 mm. in length. Female beetles tunnel into the xylem of twigs, branches, or small caliper tree trunks, and they push sawdust-like pellets (frass) out of shot-sized exit holes bored through the bark. The frass may stick together and slowly exude from the holes causing infested trees to become festooned with tan colored toothpick-like spines of frass protruding out of the bark. Wind and rain often prevent the expression of this classic symptom, with the frass falling to the ground and accumulating at the base of the tree.
As the females bore into the tree, they introduce a symbiotic ambrosia fungus which serves as food for the larvae. The fungus grows throughout the xylem and eventually disrupts vascular flow. Branches or entire trees may eventually die from a combination of fungal proliferation coupled with adult and larval wood boring activity. The fungus is easy to culture and provides a confirmation of Asian ambrosia beetle infestations. Cut infested stems in half lengthways and place them in a plastic bag with moist paper toweling. The fungus will appear within 24 hours as a white, soft, hair-like growth covering the cut surface. Unlike fungi associated with other ambrosia beetles, the fungus carried by the Asian version does not stain wood blue.
In Ohio, this beetle has been found most often on magnolias, but elsewhere in the U.S., it has been found infesting ornamental and fruit cherries, peach, plum, Japanese maple, golden rain tree, dogwood, sweet gum, oaks, elms, and azalea. Unlike other ambrosia beetles that attack stressed plants, this beetle attacks healthy plants as well as stressed plants. They also show a distinct preference for small caliper trees. Controls include insecticide bark applications and the removal and destruction of heavily infested trees. Chemical controls may include pyrethroid insecticides such as permethrin or cyfluthrin. Applications must be made to trunks and branches at 4-week intervals throughout the growing season.
Although Asian ambrosia beetle is occasionally found in landscape trees, it is generally considered a nursery pest because high populations can rapidly develop on young trees grown in close quarters. Growers do need to be aware of this serious pest and scout for it.
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GYPSY MOTH DE Ja VU
Last week's article on the gypsy moth was a byte with old information. Kudos to those who brought this to our attention, or who simply thought to themselves, "First hatch should have happened in Clark County weeks ago (April 16, 2005 to be exact)."
Although most of Ohio has experienced gypsy moth egg hatch, Randy Zondag in Lake County is still waiting. Once hatched, the caterpillars climb into tree canopies and begin their feast. If their first tree is not to their liking, they produce a silken thread, which can carry them in the wind, like a balloon, to more suitable hosts. Their feeding continues throughout the rest of the spring and early summer.
Gypsy moths can feed on leaves of more than 300 species of trees and shrubs. Favorites include oaks, aspens, birches, lindens, sweetgum, crabapples, hawthorns, mountain ash, and willows. Gypsy moth caterpillars can also be a significant nuisance when populations are high. They have a tendency to hang-out on the sides of homes and other structures, and can produce large quantities of frass (fecal pellets), which fall from tree canopies (ie: gardens, pools, patios, and driveways).
Each caterpillar can consume between 25 and 35 leaves in a season. The majority of this feeding is done by older caterpillars during the end of June, sometimes making it appear as if trees are stripped of leaves practically over night. But if you wait to see the severe damage, options for control are limited and usually not as successful as those made when the caterpillars are small.
Successful management of gypsy moths requires an integrated approach based on a number of techniques. When population densities are high, the safest and most effective tool for preventing widespread defoliation is aerial applications of an insecticide derived from the naturally occurring bacterium, Bacillus thuringiensis, commonly know as Bt. The Bt sprays used for gypsy moths affect only caterpillars feeding at the same time, and are harmless to all other animals, including bees and other insects, birds, pets, and humans. Bt must be used when the caterpillars are at earlier instars. It is not effective if they are large munching machines.
Currently, the Ohio Department of Agriculture is treating identified areas that applied to the state last fall for treatment. These areas had to meet the state's requirements to be included in the 2005 program. Pre-recorded daily updates on planned treatment blocks is available by calling 614.387.0907, after 6:00 p.m. Maps of ODA treatment blocks can be viewed at www.ohioagriculture.gov by clicking on "gypsy moth."
In regions where gypsy moths has been established for a number of years, natural controls help keep populations in check during most years. Natural enemies include insect parasites that attack egg and caterpillar stages, predators such as birds, and disease organisms. Gypsy moths are especially susceptible to a virus that is often responsible for the crash of high populations. A fungal disease of gypsy moths called Entomophaga maimaiga has been introduced in Ohio and is a promising tool for gypsy moth management.
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TICK TESTIMONIAL
David Goerig reported the Mahoning County Extension office was asked to identify a tick this past week. The concerned mother had removed it from her child, and knew exactly where she could take it to be identified. The suspect arachnid turned out to be the AMERICAN DOG TICK, Dermacentor variabilis (Say). American dog ticks are the most frequently encountered tick in Ohio, even though 12 species are known to occur here. They are easily identified by the light and dark brown mottled color patterns. Ticks are also known to possess harpoon-like barbs along their mouths that are backed up with eight crablike legs along their one piece, oval bodies. These physical features help to hold them to the host they feed upon.
American dog ticks are three host feeders. Specifically, each development stage feeds on a different host. As soon as the eggs hatch, usually in the early spring, the small six- legged larvae attach and feed on small mammals, such as the white-footed mouse and the meadow vole. After less than a weeks time they dislodge from their host, shed their skin, and begin to develop another pair of legs. The second host will be another small rodent which will give the tick enough nourishment to grow to an adult size. Adult ticks mate and feed on larger mammals, including dogs and humans. Adults are most abundant from mid-April to mid-July. Female ticks are known to be prolific egg layers.
American dog ticks prefer overgrown vacant lots, waste farm fields, hiking trails, and other habitats with tall herbaceous plant material. They wait on these plants for a suitable host to brush against them. At that point they use their barbs and claws to latch on. Once on a suitable host, they crawl upward and take a bloodmeal. Ticks are known vectors of diseases and should be removed promptly from humans and pets. Manage tick populations around your business or home mechanically by removing their basic habitat. This can be accomplished through string trimming and/or mowing tall herbaceous plant materials. Extra precautions need to be taken if your pet[s] lives indoors.. Chemical controls are available that will control populations as well as work as repellents.
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WINDSHIELD WIPE
BYGLers also ran into a few other insects and mites this week, including:
* Joe Boggs reported that pine spittlebug masses are just becoming evident on Scotch pine and Eastern white pine in southwest Ohio. Like aphids, spittlebug nymphs suck plant juices and tend to withdraw more water and carbohydrates than they can utilize. They cover themselves with excessive fluid withdrawn from the plant and produce the "spittle" by bubbling air from the tip of the abdomen into the liquid. Consequently, Dave Shetlar has long contended that these insects should be named, "anal bubblebugs". This pest seldom achieves damaging population levels under landscape conditions, although heavy infestations may stunt or kill shoots.
* First generation of EUONYMUS SCALE (Unaspis euonymi) nymphs are now appearing in southwest Ohio. The event was nicely predicted by two indicators: Growing Degree Day (GDD) accumulation (406); and the full bloom of 'Miss Kim' lilac (Syringa patula). Females of this armored scale insect are protected from insecticides by a hard, grayish to brown waxy cover, or "test." The mobile, yellowish-tan first instar nymphs (crawlers) are the life stage of this insect that is most susceptible to insecticides. Control can be achieved using a wide variety of insecticides labeled for euonymus, including soaps and horticultural oils. Refer to OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials," for a complete list of control materials.
* BOXWOOD LEAFMINER (Monarthropalpus flavus) adults are buzzing their namesake in southwest Ohio. The tiny midge flies look like reddish-orange miniature mosquitoes. Adults can be targeted with a foliar application of acephate (e.g. Orthene). However, an application of imidacloprid (e.g. Merit) made as a soil drench is a more effective control. While fall is the ideal timing for this application, since it will also prevent damage from BOXWOOD PSYLLIDS (Psylla buxi), an application made now will kill larva as they begin to develop in leaf mines.
* BYGLers reported that the handiwork of several gall-making mites in the family Eriophyidae are now appearing, and available for appreciation. These include: the light-green to reddish-green, finger-like "spindle galls" on the upper leaf surface of sugar maple, caused by the eriophyid Vasates aceriscrumena, and on the upper leaf surface of black cherry, caused by Phytoptus cerasicrumena (the "cherry-ophyid mite"); and the globose, pouch-like "bladder galls" on the upper leaf surfaces of red and silver maples, caused by V. quadripedes. The craftsmanship of the eriophyid, Aculops toxicophagus, is just now becoming apparent on poison ivy, as irregular, wart-like green to reddish-green galls on the upper leaf surface...looking much like the handiwork of poison ivy on the upper skin surface of gardeners.
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DISEASE DIGEST
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VERTICILLIUM WILT
BYGLers have recently received a number of questions about Verticillium wilt, especially on maples. For example, one nursery observed considerable vascular streaking in stems on plants that had only been planted three weeks earlier. The question was whether or not it was likely that this infection and streaking was due to root infections on these trees at that site. This seems very unlikely; the vascular streaking on these trees is a result of root infections made some time previously. For example, when the plants were in their original liner location, prior to being sent to the nursery that noted the problem this spring.
The Verticillium albo-atrum fungus has a broad host range of plants that it infects, including many common woody ornamentals. A partial list of common susceptible hosts includes: ash, azalea, barberry, catalpa, cherry and other stone fruits, daphne, elm, honeysuckle, lilac, magnolia, maple, Russian olive, peony, privet, redbud, rose, serviceberry, smoketree, spiraea, tree-of-heaven, tuliptree, viburnum, and yellowwood.
Plants with good resistance include all gymnosperms (pine, spruce, fir, hemlock, yew, ginkgo, etc.), and all monocots (grasses, sedges, lilies, palms, etc.). A partial list of other resistant plants includes: mountainash, beech, birch, crabapple, dogwood, sweetgum, hackberry, hawthorn, hickory, holly, linden, honeylocust, oak, pawpaw, pear, planetrees, rhododendron, walnut, and willow.
The Verticillium fungus infects plants through the roots, moving upward via the vascular system. Environmental factors that affect Verticillium infection and subsequent disease development include moisture stress, root injury, damage from salts, transplant injury, and other factors that affect root health. Indeed, the factors affecting wilt incidence and severity include all three angles of the disease triangle: 1) Host plant susceptibility to infection by the Verticillium pathogen; 2) The effects of environmental factors on infection; and 3) Degree of virulence of the strain of the Verticillium pathogen.
Be careful when trying to diagnose Verticillium wilt disease. Symptoms include leaf scorch and wilt, branch dieback (often one or a few at a time and often leading to plant death), excessive suckering, and brownish, greenish or reddish streaking of the vascular tissue. Discoloration in the wood, though, can be caused by other non-pathogenic fungi. On the other hand, some trees, such as ash, are notorious for confusing the issue by seldom expressing this vascular discoloration symptom of a Verticillium infection.
Samples sent to the PPDC for confirmation should include twigs with entire leaves that are still attached to the tree but exhibit scorch symptoms. The fungus may be isolated from the leaf petioles. To allow for isolation of the fungus from branch tissue, 6" to 8" sections of wood about 0.75"-1" in diameter taken from branches with scorched leaves, should also be sent. As with all samples sent to the Clinic, it is best to send them early in the week and by "overnight" delivery.
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MOIST CHAMBEr
Cool, moist conditions in the past two weeks are quite conducive to a number of fungal disease problems.
* Randy Zondag reports serious problems with DOWNY MILDEW OF ROSE in overwintering and greenhouse situations with roses this year. This not surprising considering the cool conditions.
* The low temperatures and moist weather will also probably result in a number of ANTHRACNOSE problems on late-leafing trees such as sycamores and oaks. Typically, trees can tolerate considerable anthracnose. Sycamore, oak and ash regularly recover well from early season leaf blotching and drop from anthracnose as the weather warms and new leaves develop.
* A number of BYGLers reported BOTRYOSPHAERIA DIEBACK (BOT ROT) on plants such as viburnum and redbud. For the most part, Botryosphaeria species attack stressed plants, such as viburnums that have suffered from drought stress in the past and redbuds which are planted in exposed locations. Pruning out branches with discolored, wilted and absent foliage a few inches back of the rough, cracked Botryosphaeria cankers is the best control approach for this disease in the landscape as opposed to trying to use preventive fungicide sprays since these infections.
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TURF TIPS
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BLUEGRASS SEEDHEADS PREVALENT
ANNUAL BLUEGRASS (Poa annua) is one of the five most widely distributed plants in the world (Fenner, 1985*). It frequently invades heavily trafficked, closely mown, intensely managed turf but can be found just about anywhere. At this time of year, it is most noticable because it has prolific seedheads and is usually apple-green in color. Historically, advice on controlling Poa in turf has been to treat the area with a non-selective herbicide and re-seed because there have been no selective products that can take Poa out of a desirable turf.
Research into herbicide products is ongoing. At Ohio State, Dr. John Street is working with herbicides and plant growth regulators to look at Poa control and/or seedhead suppression. One of the newer chemicals "Velocity" appears to have great control over Poa but it's effect on turf toxicity in the short term are still being evaluated. Purdue has produced an informative factsheet on Poa annua and Poa trivialis (PDF document) that can be accessed at:
*Reference: Fenner, M, 1985. Seed Ecology, Chapman & Hall, London.
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DANDELION CONTROL
Dandelions will thrive in compacted areas that have low fertility & sporadic mowing. To minimize dandelion invasion, regular mowing and a balanced fertilizer program should keep grass healthy enough to out-compete broadleaf weeds like dandelions. If turf areas do have dandelion problems now is the time to control them. After the dandelions have set seed, energy is focused on root development, so there is a downward flow or transpiration within the plant. This happens in the late fall too, before the onset of winter. This downward flow can be capitalized on ... the applied herbicide is taken to the underground storage system (in this case a tap root) and is far more likely to kill the plant. If there are a lot of dandelions, a consecutive application should be made in late fall.
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CRABGRASS UPDATE
In central Ohio, crabgrass germinated several weeks ago, so the window of opportunity for applying preemergence herbicides is closed. More northern regions e.g. NE Ohio, that had frost and unseasonable cold weather last week may still have some preemergence success. Once the preemergence window is closed one of the most effective chemicals to use for crabgrass control is Dimension (Dithiopyr). It has both pre- postemergence activity.
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WATCH OUT FOR CHINCH BUGS
Both CHINCH BUGS and BILLBUGS have resumed activity after their winter respite, and potentially can reach damaging levels before they are noticed. Jennifer Andon, Dr. Shetlars graduate student, found 350 chinch bug eggs from one cup cutter- sized sample this last week! Billbugs have already begun laying eggs at the base of Kentucky bluegrass stems, and can be seen wandering on sidewalks adjacent to turfgrass on sunny days.
If chinch bugs or billbugs were present and causing damage to turfgrass last year, treat now in central Ohio with a recommended insecticide. Both bifenthrin (Talstar) and deltamethrin (Delta Guard) (*both available for homeowners), provide good control of both insects. Imidacloprid (Merit) can be applied in mid May - June to suppress these pests, as well as to control annual grub populations this fall. Check for the presence of either insect before applying the insecticide.
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TURF WHEATIES?
Joe Rimelspach and Joe Boggs reported they received several calls concerning winter wheat sprouting in turf in central and southwest Ohio. Cases of mistaken seed purchases? Contaminated turf seed?? Victims of Johnny Wheat-seed??? No, in each case the turf had been seeded in the fall and covered with wheat straw that obviously contained viable wheat seed.
Winter wheat is an annual plant and it behaves as a winter annual weed in lawns. The plants will eventually die during the summer; however, a heavy wheat infestation in a lawn can create a number of problems. The light green wheat plants are thick bladed and do not blend with turfgrasses. Multiple coarse stems left behind when the wheat plants are mowed further reduces the aesthetic quality of lawns. Also, the rapid growth of wheat plants far outpaces the growth of turfgrass. The bolting wheat quickly rises above newly mowed lawns rapidly degrading lawn quality.
After the wheat plants die the space occupied by the plant becomes a hole in the lawn. This occurs during the time of the year when cool-season grasses are growing at their slowest pace. Consequently, surrounding turfgrass plants may fail to fill these holes. Lawns that are heavily infested with wheat may become weed-infested lawns when open areas left by the dead wheat are invaded by weed plants.
Finally, cases of mistaken identity could lead to disastrous weed management decisions. Grassy weed identification in turfgrass is not an easy task, and the appearance of wheat in a lawn is not something most turf managers expect. Wheat shares identification features with some very serious grassy weeds. For example, wheat has auricles. These are appendage-like structures that grow from the base of the blade where blade meets the grass stem. Quackgrass, which is a perennial grassy weed also has auricles. Of course, management decisions for the two problems are very different. Killing quackgrass involves applying a non-selective herbicide, such as glyphosate (e.g. Roundup). There is no point in using an herbicide to kill the wheat, and surrounding turfgrass the wheat is going to die anyway.
BYGLers could not arrive at a best answer for preventing wheat from infesting newly seeded turfgrass. They lacked an explanation, but all agreed that the problem seems to be more common in recent years. The best recommendation is to hand pull as many of the wheat plants as possible, before they grow past the seedling stage. Then, be prepared to apply turfgrass seed and water to open spots left by the departing wheat plants in the summer.
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INDUSTRY INSIGHT
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A note of thanks to the Mahoning County Landscape, Nursery Association for their generous support to the Mahoning County Extension Office. During these challenging times when county government budgets are tight, it is reassuring to know that people and organizations recognize extension as a valuable service.
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COMING ATTRACTIONS
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SALSA (SECREST ACADEMY FOR LANDSCAPE SCIENCES AND ARTS)
This "churning urn of burning funk" of a horticultural program starts this summer at OSU's Secrest Arboretum at the Ohio Agricultural Research and Development Center in Wooster. It is for individuals with professional or personal interest in an intensive, hands-on landscape learning experience and is a program of Ohio State Universitys Secrest Arboretum and the Ohio State University Extension Center at Wooster. Faculty for session I of SALSA are Jim Chatfield, Ken Cochran, Joe Cochran and Erik Draper.
SALSA I will focus on the following topics: Making Plant Names Work For You, Discovering How Plants Grow, Selecting Plants for Landscape Solutions and Minimizing Maintenance, Diagnosing Plant Problems, Putting Plants in their Place, and Producing Plants: From Propagation to Pricing. SALSA I will involve three full-day sessions on July 18, August 15, and September 19 and is part of a five-part, 15 session/15 month overall Academy.
SALSA is a learning experience, advancing your knowledge of the arts and sciences of landscape horticulture, through linked interactive hands-on programs. SALSA is not a series of isolated single-topic programs, nor it a full-fledged 2- or 4- year degree program. SALSA occupies the landscape between these two...rooted in dedication, blooming with creativity. Class size is limited. The cost of SALSA I is $300 for the full three days of programming. This fee includes considerable reference material and class curriculum notebooks, diagnostic aids such as hand lens, lunches and refreshments. For more information contact Joe Cochran at Secrest Arboretum (330-263-3886; cochran.58@osu.edu).
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OHIO PLANT DIAGNOSTIC WORKSHOPS
There are a number of OSU Extension Ohio Plant Diagnostic Workshops coming up in June. Typically the workshops run from 10-4 with several talks, a walking tour, and extensive discussions of diagnostic samples. Here is a list to get on your calendar. More details will follow next week following our final planning sesssions.
June 2: OSU Extension, Clark County (for Master Gardeners)
June 6: OSU Extension, Hamilton County (green industry and others)
June 7: OSU Extension, Lake County (as part of Randy Zondag's regular IPM session)
June 24: OSU Extension, Franklin County (green industry)
June 29: OSU- Secrest Arboretum, Wooster (green industry; one hour program)
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THE FIRST DIAGNOSTIC WALKABOUT
The Diagnostic Walkabout in the greater Cleveland area this summer occurs Thursday May 26 in the North Olmsted area. Charles Behnke and Tim Malinich, horticulture educators with Ohio State University Extension, will take a critical look at landscape and turf problems during the early morning walkabouts. Recertification credit available for 8 and 6A. Call 216-397-6023 to request a registration flyer with more information.
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BYGLOSOPHY
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"Nature rarer uses yellow
than another hue-" -Dickenson
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